Subsets of patients will be selected for repetitive studies of their peripheral arterial and extracranial arterial systems. These include patients with peripheral neuropathy to establish its relationship to peripheral atherosclerosis. The effects of hyperglycemia per se as manifested in patients with pancreatic disease will also be studied and compared to matched diabetic patients. Lastly, the association of hyperlipoproteinemia in the adult onset diabetic with peripheral and extracranial atherosclerosis will also be evaluated. The methods to be employed will include segmental limb pressures, arterial velocity patterns, exercise testing, oculoplethysmography, phonoangiography and ultransonic studies of the carotid bifurcation. In addition, those known risk factors which may play a contributory role in the genesis of atherosclerosis will be collected from the records of the treating clinics in the four hospitals in the University system. All patients will be studied annually unless they are found to have arterial disease or a peripheral neuropathy. These studies will be carried out every six months in these patients.